Creation of metal materials nanoporous structures under the action of laser radiation

The laser radiation exposure for creation ofnanoporous structures in the Cu-Zn alloy wasstudied. Exposure to laser pulse-periodic radiationwith pulse repetition rate up to 5000 Hz makes itpossible to form a nanoporous structure in the nearsurfacelayer. The modes of an increase of the areadepth of such structures formation up to 40...45 μmwere ascertained. The temperature and speed modeswhich provide predominant channel-type nanoporesformation with widths of about 100 nm forming ananoporous net were investigated

Optical elements based on silicon photonics

Silicon photonics is gaining substantial impulse because it permits optical devices to be realized inexpensively using standard semiconductor fabrication techniques and integrated with microelectronic chips. In this paper, we designed few optical elements such as optical power splitter, polarization beam splitter and Bragg grating based on silicon platform simulated using finite element method.This work was financially supported by the Russian Foundation for Basic Research (grant No. 16-29-09528_ofi_m) for numerical calculations, by the Ministry of Science and Higher Education within the State assignment FSRC "Crystallography and Photonics" RAS (No. 007-GZ/Ch3363/26) for theoretical results

UV-LIGA fabrication process for realization of metal based MEMS gyroscope

This paper reports the complete fabrication process flow based on UV-LIGA technology for realization of metal based MEMS gyroscope. In this process, nickel is used as the structural layer and copper as the sacrificial layer. The economical three mask process has been optimized and the detailed step by step procedure for carrying out the fabrication is presented. The fabrication results after each process step have been presented and discussed. Scanning electron micrograph images of the released prototype gyroscope devices have been presented to demonstrate the successful fabrication of the prototypes

Analytical modeling of synchronous demodulation of a multi-DOF gyro-accelerometer

This paper reports a analytical model of a 4-DOF gyro-accelerometer consisting of 2-DOF drive and 2-DOF sense oscillators configured orthogonally. A detection scheme for time varying angular rate and linear acceleration, by combining the structural-model of gyro-accelerometer with the processes of synchronous demodulation and filtration, has also been spelt out to investigate frequency responses at the event of angular motion and linear acceleration. Finally, the results of the model have been validated by comparing with MATLAB®/Simulink data which shows excellent matching with each other

ANALYSIS ОF THE 3D STRUCTURE ОF MICRO IRREGULARITY ON THE SURFACE OF THE MACHINE-BUILDING DETAIL

The operational properties of the parts depend on the roughness of its surface. The technological impact can control the structure of surface microroughness. The necessary structure of roughness can be broken by inclusions of different nature (carbides, impurities, phases). We offer a digital filer for image processing of a rough surface. The advantage of the filter is the selection of the microroughness structure on the image without inclusions. The cleaned image allows to predict the operational properties of the surface

Analytical design of refractive optical elements generating a prescribed two-dimensional intensity distribution

Предложен новый вид лучевого отображения в задаче расчёта преломляющих оптических элементов для формирования заданных двумерных распределений интенсивности. Предложенное отображение позволяет свести расчет преломляющего оптического элемента к решению обыкновенных дифференциальных уравнений 1-го порядка, разрешенных относительно производной. Результаты расчета показывают высокие рабочие характеристики предложенного метода. При формировании прямоугольных равномерных распределений интенсивности с размерами от 80°×1° до 40°×20° относительная среднеквадратичная ошибка формирования заданной интенсивности не превышает 15 %. A new source-target mapping for the design of refractive optical elements generating prescribed 2D intensity distributions is proposed. The calculation of the optical element is reduced to the solution of ordinary explicit differential equations. The simulation results presented demonstrate high performance of the proposed method. While generating uniform rectangular intensity distributions with angular dimensions varying from 80°×1° to 40°×20°, the normalized root-mean-square deviations between the generated and required distributions do not exceed 15 %.Работа выполнена при поддержке Российского научного фонда (проект №18-19-00326)

Design of optical elements for an extended light source

Using the previously developed optimization method for an extended light source [Byzov EV, Kravchenko SV, Moiseev MA, Bezus EA, Doskolovich LL. Optimization method for designing double-surface refractive optical elements for an extended light source. Opt Express 2020; 28(17): 24431-24443. DOI: 10.1364/OE.400609], we designed a compact refractive optical element (the ratio of the element height to the light source size being 1.55) providing a uniform illuminance distribution in a shifted rectangular region. An application of the optimization method for calculating the so-called TIR-elements, exploiting the phenomenon of the total internal reflection of rays, is considered. For an extended light source, compact TIR-elements with freeform exit surfaces that generate uniform illuminance distributions in a rectangular region are designed. The results of the work show promise for a wide class of problems of designing compact optical elements for light-emitting diodes